Furnace structure.



J. EGGINS.

FURNACE STRUCTURE. APPLICATION FILED D160. 5, 190a. RENEWED 00-12. 8, 1910.

975,754. Patented Nov 15, 1910.

W ITNESSES INVEN'TUR l f -L.

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JAlVfES EGGINS, OF OTTAWA, ONTARIO, CANADA.

FURNACE STRUCTURE.

Application filed December 5, 1908, Serial No. 466,180;

To all whom it may concern:

Be it known that I, JAMES EccINs, of No. 79 Bank street, in the city of Gttawa, in the Province of Ontario, in the Dominion of Canada, have invented certain new and useful Improvements in Furnace Structures; and I do hereby declare that the following is a full, clear, and exact description of the same.

The invention relates to improvements in a furnace structure, as described in the present specification, and illustrated in the ac companying drawings that form part of the same.

The invention consists essentially in the novel arrangement and construction of parts whereby the bed of the furnace structure is raised toward the rear thereof forming a combustion chamber immediately to the rear of the bridge wall, said combustion chamber being supplied with heated air by a chamber formed in said bridge wall at the rear thereof and having inlet fiues extending in proximity to the fire box from the exterior of said furnace structure.

The objects of the invention are to devise a furnace structure, which will provide for the complete combustion of fuel in a simple and eiiicient manner without the aid of forced draft or other power contrivance, which will be strong and durable and will pass the heated products of combustion in close proximity to the boiler, thereby greatly increasing the heating properties of the furnace.

In the drawings, Figure 1 is a sectional perspective view of the furnace structure. Fig. 2 is a cross sectional view through the line A B in Fig. 1 looking toward the front of the furnace. Fig. 3 is a perspective detail of one of the hot-air fines. Fig. 4 is a perspective detail view partly broken away of the hot-air chamber.

Like numerals of reference indicate corresponding parts in each figure.

Referring to the drawings, 1 are the side walls of the furnace structure, 2 the fire box, 3 the ash-pit and 4 the bridge wall, as customary in furnaces.

5 is a rectangular box set in the bridge wall 4 at the back thereof and flush with the rear face of said bridge wall, said box forming a hot-air chamber and having the openings 6 at the lower corners through one side thereof, and the orifices 7 extending in a row Specification of Letters Patent.

Patented Nov. 15, 1910.

Renewed October 8, 1910. Serial No. 586,106.

along the upper part of the other side thereof.

The box 5 extends laterally of said fur-- nace structure for a short distance into each of the side walls 1, the bridge wall 4 being built up over said box 5 in substantially arcshape to conform with the contour of the under side of the boiler.

8 are fiues preferably square in cross sec-- tion, said flues being embedded in the side wall 1 of the furnace structure to each side of the fire box 2 and extending from the front plate 9 to the openings 6 in the box 5, one side of each of the fines 8 being flush with the inner face of the side walls 1, thereby being exposed to the heat of the fire box,

so that the air in passage through said fines becomes very hot by the time it reaches the box 5. The exposed side of the flues 8 is preferably thicker than the remaining sides to withstand the intense heat.

The flues 8 are preferably inclined slightly from the front plate 9 to the box 5 to cause the air to pass rapidly therethrough into the box 5 as it becomes heated, said flues at the entrance thereof being provided with the dampers 10 to regulate the quantity of air passing therethrough.

The rear of the furnace structure is filled in at 11 with any suitable material, such as old brick or cinders, and covered with fire brick and a facing of fire clay to form the raised bed 12 extending from a point adjalgenlt to the bridge wall to the rear end of the o1 er.

The bed 12 is formed are-shaped in cross section to form a substantially crescentshaped passage between the bottom of the boiler and said bed.

The bed 12 adjacent to the bridge wall 4 curves downwardly at 13 to form the com bustion chamber 14 between the bed 12 and the bridge wall 4 and into which the hot air is emitted from the orifices 7 in the box 5.

15 is a clean-out door arranged in the side wall 1 of the furnace structure at the bottom of the combustion chamber 14, and 16 is a clean-out door arranged in the side wall 1 of the furnace structure at the rear thereof, where the bed 11 terminates to form the soot chamber 17 as customary in furnaces. The gases emitted from the burning fuel in the fire box, as they pass over the bridge wall 4, swirl downwardly into the combustion chamber 14, where they commingle with the hot air emitted into said combustion chamber through the orifices 7 in the box 5 and complete combustion of all gases is thereby obtained. The combusted gases then pass over the curved portion 13 of the bed 12 and along said bed, which holds the hot gases into proximity to the boiler, so that all the heat units possible are derived from said gases by the boiler, after which the gases pass through the fines or other part of the furnace structure as customary.

As hereinbefore explained the quantity of air emitted from the orifices formed in the box 5 is regulated by the dampers 10 at the openings to the fines 8,'and the air passing through the fines 8 is heated to an intense degree by the fire, which is immediately against one side of said flues. At the same time it is an advantage to have these lines raised slightly toward the box 5, so that the air passing therethrough, on being heated, will create a draft and cause quite a pressure of air in the box 5.

The formation of the bed 12- of the furnace structure must be here emphasized, as the heated gases are considerably compressed, as they pass between the bridge wall 4 and the boiler, and as soon as they are freed from the bridge wall the combustion chamber gives them room for expansion, which sets up swirling eddies of gases as indicated by the arrows in Fig. 1, thereby assuring the thorough mixture of the hot air emitted from the orifices 7 with said gases. The raised bed 12 also influences the gases as they pass over the bridge Wall to slightly check them and swirl them in the combustion chamber until the final products of combustion becoming intensely heated force their Way along the passage between the bed 12 and the under side of the boiler, the said bed holding the gases in continuous contact with the under side of the boiler until the rear of the furnace is reached, where it is customary in furnaces to return the gases again through the fines of the boiler.

It will thus be seen that it is not only heating of the air admitted into the furnace alone that provides for complete combustion of the gases arising from the fuel in the fire box 1, but the entire arrangement of the furnace structure so manipulates the gases and the heated air that thorough combustion is assured.

What I claim as my invention is:

In a furnace structure, the combination with the fire-box and bridge-wall thereof, of a hot-air box embedded in said bridge-wall and extending laterally of said furnace structure and having the rear face thereof flush with the rear face of said bridge-wall and having a plurality of orifices from the rear side thereof toward the top and openings at the lower corners of the front side thereof, fiues having an uninterrupted passage and extending direct from the front plate of said furnace structure to the openings in said hot-air box, said fiues being inclined upwardly toward said box and having one side thereof exposed to said fire-box and of greater thickness than the remaining sides and a-raised bed having a concave upper surface extending over the greater portion of the length of said furnace structure toa ward the rear thereof dipped downwardly adjacent to said bridge wall and forming an auxiliary combustion chamber between the rear of said bridge-Wall and said raised bed.

Signed at the city of Ottawa, county of Carleton, Canada, Province of Ontario, this 24th day of November, 1908.

J AMES EGGINS.

Witnesses LLOYD BLACKMORE, REN PIGEON. 

